Modify the description of focusableArea

* Remove redundant description
 (Finding focusable areas already returns DOM anchor, therefore `anchor` variable isn't necessary.)

Author: Jihye Hong

css-nav-1/Overview.bs

@@ -499,17 +499,15 @@ the User Agent must run the steps described below:
         if <var>option</var> is present and its value is equal to <code>'all'</code>,
         or <code>true</code> otherwise.
     2. Let <var>areas</var> be the result of <a>finding focusable areas</a> within the element with <var>visibleOnly</var> as argument.
-    3. Let <var>anchors</var> be a <a for=list>clone</a> of <var>areas</var>,
-        with every <a>focusable area</a> which is not itself a <a>Node</a> replaced with its <a>DOM anchor</a>.
-    4. Return <var>anchors</var>
+    4. Return <var>areas</var>
 
 </div>
 
 <div class=example id=focusAreas-visible>
     The following code shows how to get all the visible focusable elements in the current page using {{Element/focusableAreas()}}.
     If the method finds a <a>spatial navigation container</a>, it recursively finds focusable areas inside it.
-    However, as the {{FocusableAreasOption/mode}} attribute of this method is set to <code>visible</code>,
-    the focusable element which isn’t inside the <a>scrollport</a> is excluded from the result.
+    Because the value of the {{FocusableAreasOption/mode}} attribute in this method is <code>visible</code>,
+    the focusable elements which aren't inside the <a>scrollport</a> are excluded from the result.
 
     <pre><code highlight=markup>
     &lt;body>